KR20070046592A - A composition for preparing an electron emission source, a method for preparing an electron emission source by using the same and the electron emission device comprising the electron emission source prepared by using the method - Google Patents

Abstract

The present invention provides a composition for forming an electron emission source comprising a carbon-based material, a vehicle, a hydrophilic group-containing photosensitive resin, and a water-soluble photoinitiator, a method for producing an electron emission source using the same, and an electron emission device having an electron emission source manufactured using the same. It is about. By using the composition for forming an electron emission source, a problem that a residue remains after development of the composition for forming an electron emission source may be solved.

Description

A composition for forming an electron emission source, a method of manufacturing an electron emission source using the same, and an electron emission device having an electron emission source manufactured using the same, a method for preparing an electron emission source by using the same and the electron emission device comprising the electron emission source prepared by using the method}

1 is a cross-sectional view schematically showing an embodiment of an electron emitting device of the present invention.

<Short description of drawing symbols>

110: lower substrate 120: cathode electrode

130: insulator layer 140: gate electrode

160: electron emission source 170: phosphor layer

180: anode electrode 190: upper substrate

The present invention relates to a composition for forming an electron emission source, a method for producing an electron emission source using the same, and an electron emission device having an electron emission source manufactured using the same. More specifically, the present invention relates to a hydrophilic group-containing photosensitive resin and a water-soluble photoinitiator. The present invention relates to a composition for forming an electron emission source, an electron emission source manufacturing method using the same, and an electron emission device having an electron emission source manufactured using the same. The composition for forming an electron emission source as described above can be easily developed by a water-soluble developer and leaves substantially no residue. Therefore, by using the electron emission source manufactured using the composition for forming an electron emission source, an electron emission device having improved reliability can be obtained.

An electron emission device emits electrons from an electron emission source of a cathode electrode by applying a voltage between the anode electrode and the cathode electrode to form an electric field, and impinges the electrons on a fluorescent material on the anode electrode side to emit light. It is an element.

Carbon-based materials including carbon nanotubes (CNTs), which have excellent electronic conductivity, have excellent conductivity and field concentration effects, low work function, and excellent field emission characteristics, so that low-voltage driving is possible and large area is possible. It is expected to be an ideal electron emission source for electron emission devices.

The method for producing an electron emission source containing carbon nanotubes includes, for example, a carbon nanotube growth method using a CVD method or the like, a paste method using an electron emission source formation composition containing carbon nanotubes and a vehicle. By using the above paste method, the manufacturing cost is low and the electron emission source can be formed in a large area. Compositions for forming electron emission sources, including carbon nanotubes, are described, for example, in US Pat. No. 6,436,221.

However, according to the conventional method for producing an electron emission source using the paste method, the composition for forming an electron emission source and the photoresist pattern for electron emission patterning are simultaneously developed (that is, unexposed electrons) using an organic solvent such as acetone. Removal of the source forming composition and the photoresist pattern). In this case, residues generated on the photoresist pattern may remain without being removed by a chemical reaction between the photoresist pattern and the composition for forming an electron emission source. That is, the residue of the composition for forming an electron emission source may remain in the electron emission source non-forming region. This may cause abnormal light emission of the electron emitting device, and thus an improvement thereof is necessary.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above, and an object thereof is to provide a composition for forming an electron emission source that does not substantially leave a residue of the composition for forming an electron emission source in an electron emission source non-forming region. do. In addition, a method of manufacturing an electron emission source using the composition for forming an electron emission source, and an electron emission device having an electron emission source manufactured from the composition for forming an electron emission source is also provided.

In order to achieve the above object of the present invention, the first aspect of the present invention provides a composition for forming an electron emission source comprising a carbon-based material, a vehicle, a hydrophilic group-containing photosensitive resin and a water-soluble photoinitiator.

In order to achieve the above object of the present invention, a second aspect of the present invention provides a composition for forming an electron emission source as described above, and forms a photoresist pattern defining an electron emission source formation region on a substrate. Printing and exposing the composition for forming an electron emission source on a substrate on which the photoresist pattern is formed; developing the exposed composition for forming an electron emission source with a water-soluble developer; and removing the photoresist pattern. And it provides a method for producing an electron emission source comprising the step of firing the developed composition for forming an electron emission source.

In order to achieve the another object of the present invention, a third aspect of the present invention, the first substrate and the second substrate disposed to face each other, the cathode electrode formed on the first substrate, and the cathode electrode and electrically An electron emission source formed to be connected, an anode electrode formed on the second substrate, and a fluorescent layer emitting light by electrons emitted from the electron emission source, wherein the electron emission source forms an electron emission source as described above. Provided is an electron emitting device manufactured using the composition for use.

The composition for forming an electron emission source is effectively developed by a water-soluble developer and does not substantially leave a residue, thereby producing an electron emission source having a very precise pattern.

Hereinafter, the present invention will be described in more detail.

The composition for forming an electron emission source of the present invention provides a composition for forming an electron emission source including a carbonaceous material, a vehicle, a hydrophilic group-containing photosensitive resin, and a water-soluble photoinitiator.

First, the carbon-based material has excellent conductivity and electron emission characteristics, and thus serves to excite the phosphor by emitting electrons to the fluorescent layer during operation of the electron emission device. Non-limiting examples of such carbon-based materials include carbon nanotubes, graphite, diamond, fullerenes, silicon carbide (SiC), and the like. Among these, carbon nanotubes are preferable.

Carbon nanotubes are carbon allotropes in which graphite sheets are rounded to a nano-sized diameter to form tubes. have. The carbon nanotubes of the present invention are manufactured using a CVD method such as thermal chemical vapor deposition (hereinafter referred to as "CVD method"), DC plasma CVD method, RF plasma CVD method, microwave plasma CVD method. It may have been.

The vehicle controls the printability and viscosity of the composition for forming an electron emission source and serves to transport the carbon-based material. The vehicle of the present invention may comprise a resin component and a solvent component. Among these, the resin component may include a unit represented by the following Chemical Formula 1 and a unit represented by the following Chemical Formula 2, and may include a water-soluble polymer having a weight average molecular weight of 1,000 to 50,000:

<Formula 1>

<Formula 2>

In Formulas 1 and 2,

R ₁ and R ₄ are each independently a substituted or unsubstituted C ₁ -C ₂₀ alkylene group, a substituted or unsubstituted C ₂ -C ₂₀ alkenylene group, a substituted or unsubstituted C ₃ -C ₂₀ cycloalkylene group , A substituted or unsubstituted C ₆ -C ₂₀ arylene group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkylene group or a substituted or unsubstituted C ₂ -C ₂₀ heteroarylene group. Among them, a substituted or unsubstituted C ₁ -C ₅ alkylene group is preferable.

R ₂ and R ₅ are each independently a bonded, substituted or unsubstituted C ₁ -C ₂₀ alkylene group, a substituted or unsubstituted C ₂ -C ₂₀ alkenylene group, a substituted or unsubstituted C ₃ -C ₂₀ cycle It may be an alkylene group, a substituted or unsubstituted C ₆ -C ₂₀ arylene group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkylene group or a substituted or unsubstituted C ₂ -C ₂₀ heteroarylene group. Among them, a bonded or substituted or unsubstituted C ₁ -C ₅ alkylene group is preferable.

R ₃ and R ₆ are each independently a substituted or unsubstituted C ₁ -C ₂₀ alkyl group, a substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, a substituted or unsubstituted C ₃ -C ₂₀ cycloalkyl group, a substituted or Or an unsubstituted C ₆ -C ₂₀ aryl group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkyl group, or a substituted or unsubstituted C ₂ -C ₂₀ heteroaryl group. Of these, preferably a C ₁ -C ₁₀ alkyl group unsubstituted or substituted.

In said Formula (2), Z is a hydrophilic group. More specifically, the Z is -OA, -COOA, -SO ₂ A, -SO ₂ NH ₂ , -SO ₂ NHCOT ¹ , -T ² SO ₂ A, -SO ₃ A, -PO ₃ NH ₂ , -PO As at least one hydrophilic group selected from the group consisting of ₃ A ₂ , —NH ₂ and —N (T ¹ ) ₂ ; A is hydrogen, an alkali metal, or -NQ ¹ Q ² wherein Q ¹ and Q ² are each independently hydrogen, a C ₁ -C ₂₀ alkyl group or a C ₆ -C ₂₀ aryl group; T ¹ is a C ₁ -C ₂₀ alkyl group, a C ₆ -C ₂₀ aryl group or a C ₂ -C ₂₀ heteroaryl group; T ² may be a C ₁ -C ₂₀ alkylene group, a C ₆ -C ₂₀ arylene group or a C ₂ -C ₂₀ heteroarylene group. Among these, Z is -OH, -COOH, -SO ₂ H, -SO ₂ NH ₂ , -SO ₂ NHCOCH ₃ ,-(CH ₂ ) SO ₂ H, -SO ₃ H, -PO ₃ NH ₂ ,- It is preferably at least one hydrophilic group selected from the group consisting of PO ₃ H ₂ , -NH ₂ and -N (CH ₃ ) ₂ .

Specific examples of the unsubstituted C ₁ -C ₂₀ alkyl group used in Chemical Formulas 1 and 2 include methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl, and the like. At least one hydrogen atom is a halogen atom, nitro group, cyano group, C ₁ -C ₂₀ alkyl group, C ₂ -C ₂₀ alkenyl group, C ₆ -C ₂₀ aryl group, C ₇ -C ₂₀ arylalkyl group, C ₂ -C _And optionally substituted with ₂₀ heteroaryl groups, or C ₂ -C ₁₉ heteroarylalkyl groups.

The unsubstituted C ₂ -C ₂₀ alkenyl group used in Chemical Formulas 1 and 2 of the present invention means that it contains a carbon double bond in the middle or the end of the alkyl group as defined above. Specific examples include, but are not limited to, ethylene, propylene, butylene, hexylene, and the like. At least one hydrogen atom of these alkenyl groups may be substituted with the same substituent as in the alkyl group described above.

Specific examples of the unsubstituted C ₃ -C ₂₀ cycloalkyl group used in Chemical Formulas 1 and 2 of the present invention include, but are not limited to, a cyclohexyl group and a cyclopentyl group. At least one hydrogen atom of the cycloalkyl group may be substituted with the same substituent as in the alkyl group described above.

Unsubstituted C ₆ -C ₂₀ aryl groups used in Formulas 1 and 2 of the present invention are used alone or in combination to mean a carbocyclic aromatic system having 6 to 20 carbon atoms containing at least one ring, and at least two rings. The rings may be attached or fused together in a pendant manner. The term aryl includes, but is not limited to, aromatic radicals such as phenyl, naphthyl, tetrahydronaphthyl. At least one hydrogen atom of the aryl group may be substituted with the same substituent as in the alkyl group described above.

The unsubstituted C ₂ -C ₁₉ heterocycloalkyl group used in the general formulas (1) and (2) of the present invention includes a cyclic type having 1, 2 or 3 heteroatoms selected from N, O, P or S, and the remaining ring atoms being C. It means a hydrocarbon. At least one hydrogen atom of the heterocycloalkyl group may be substituted with the same substituent as in the alkyl group described above.

Unsubstituted C ₂ -C ₂₀ heteroaryl groups used in Formulas 1 and 2 of the present invention include monovalent mono, wherein one, two or three heteroatoms selected from N, O, P or S, and the remaining ring atoms are C It means a cyclic or acyclic aromatic organic compound. At least one hydrogen atom of the heteroaryl group may be substituted with the same substituent as in the alkyl group described above.

In the general formulas (1) and (2) of the present invention, the alkylene group, alkenylene group, cycloalkylene group, arylene group, heterocycloalkylene group and heteroarylene group are the aforementioned alkyl group, alkenyl group, cycloalkyl group, aryl group, heterocycloalkyl group and hetero It refers to a divalent radical having the same structure as each of the aryl groups. Thus, for example, non-limiting examples of C _1-20 alkylene groups include methylene groups, ethylene groups, propylene groups, butylene groups, hexylene groups and the like, and non-limiting examples of C _3-20 cycloalkylene groups Examples include cyclohexylene groups, cycloheptanylene groups, and the like, and non-limiting examples of C _6-20 arylene groups may include phenylene groups and the like.

Among the water-soluble polymers including the unit represented by Formula 1 and the unit represented by Formula 2, the molar ratio of the unit represented by Formula 1 and the unit represented by Formula 2 is 9: 1 to 5: 5, preferably May be 7: 3 to 6: 4. If the number of moles of the unit represented by the formula (1) is greater than the number of moles of the unit represented by the formula (2), the problem may occur that the water-soluble developer is not sufficiently developed, on the contrary, the number of moles of the unit represented by the formula (2) If is greater than the number of moles of the unit represented by the formula (1) is because there may be a problem that the activation of the carbon-based material is difficult and the amount of residual carbon in the electron emission source may increase.

The weight average molecular weight of the water-soluble polymer having a unit represented by Formula 1 and a unit represented by Formula 2 may be 1,000 to 50,000, preferably 3,000 to 40,000. When the weight average molecular weight of the water-soluble polymer exceeds 50,000, the synthesis of the water-soluble polymer is not easy, and when the weight average molecular weight of the water-soluble polymer is less than 1,000, printability of the composition for forming an electron emission source may be deteriorated. Because.

As described above, the water-soluble polymer of the present invention may be a polymer having a weight average molecular weight of about 10,000 to 50,000, particularly comprising a unit represented by the following formula (3) and a unit represented by the following formula (4) in a molar ratio of 7: 3. have:

<Formula 3>

<Formula 4>

.

.

The content of the water-soluble polymer including the unit represented by Formula 1 and the unit represented by Formula 2 may be 5 to 60 parts by weight, preferably 10 to 20 parts by weight, per 100 parts by weight of the total resin component included in the vehicle. . If the content of the water-soluble polymer including the unit represented by the formula (1) and the unit represented by the formula (2) is less than 5 parts by weight per 100 parts by weight of the total resin component may have a problem that it may not be sufficiently developed with a water-soluble developer When the content of the water-soluble polymer including the unit represented by Formula 1 and the unit represented by Formula 2 exceeds 60 parts by weight per 100 parts by weight of the total resin component, the viscosity of the composition for forming an electron emission source may be excessively increased. This is because the problem may occur.

The vehicle included in the composition for forming an electron emission source of the present invention may further include various resin components in addition to the water-soluble polymer having a unit represented by Formula 1 and a unit represented by Formula 2 as the resin component. For example, cellulose resins such as ethyl cellulose, nitro cellulose and the like; Acrylate resins such as polyester acrylate, epoxy acrylate, urethane acrylate and the like; At least one of a vinyl-based resin such as polyvinyl acetate, polyvinyl butyral, polyvinyl ether, and the like may be further included, but is not limited thereto. Some or more of the resin components as described above may simultaneously serve as the photosensitive resin.

The solvent component of the vehicle included in the composition for forming an electron emission source of the present invention is, for example, terpineol, butyl carbitol (BC), butyl carbitol acetate (BCA), It may include at least one of toluene and texanol. Among these, it is preferable to contain terpineol.

The content of the resin component may be 100 to 500 parts by weight, more preferably 200 to 300 parts by weight based on 100 parts by weight of the carbon-based material. On the other hand, the content of the solvent component may be 500 to 1500 parts by weight, preferably 800 to 1200 parts by weight based on 100 parts by weight of the carbon-based material. When the content of the vehicle consisting of the resin component and the solvent component is outside the above range may cause a problem that the printability and flowability of the composition for forming an electron emission source is lowered. In particular, when the content of the vehicle exceeds the above range, there is a problem that the drying time may be too long.

The hydrophilic group-containing photosensitive resin is a material that allows the electron emission source to be patterned through crosslinking when the composition for forming an electron emission source is exposed. Since the photosensitive resin contains a hydrophilic group, the composition for forming an electron emission source of the present invention including the same may be easily developed by a water-soluble developer.

For example, the hydrophilic group-containing photosensitive resin may include an acrylate resin, a benzophenone resin, an acetophenone resin or a thioxanthone resin, an epoxy resin, or a urethane resin substituted with a hydrophilic group, but is not limited thereto. It doesn't happen. The photosensitive resin may be a monomer or an oligomer, and two or more of these may be used in combination. More specifically, the hydrophilic group-containing photosensitive resin may be epoxy acrylate, polyester acrylate, 2,4-diethyloxanthone, or 2,2-dimethoxy-2- substituted with a hydrophilic group. Phenylacetophenone, urethane acrylate, and the like.

The hydrophilic group in the hydrophilic group-containing photosensitive resin is -OA, -COOA, -SO ₂ A, -SO ₂ NH ₂ , -SO ₂ NHCOT ¹ , -T ² SO ₂ A, -SO ₃ A, -PO ₃ NH ₂ , -PO ₃ A ₂ , -NH ₂ and -N (T ¹ ) ₂ ; A is hydrogen, an alkali metal, or -NQ ¹ Q ² wherein Q ¹ and Q ² are each independently hydrogen, a C ₁ -C ₂₀ alkyl group or a C ₆ -C ₂₀ aryl group; T ¹ is a C ₁ -C ₂₀ alkyl group, a C ₆ -C ₂₀ aryl group or a C ₂ -C ₂₀ heteroaryl group; T ² may be a C ₁ -C ₂₀ alkylene group, a C ₆ -C ₂₀ arylene group or a C ₂ -C ₂₀ heteroarylene group.

Among these, the hydrophilic group is -OH, -COOH, -SO ₂ H, -SO ₂ NH ₂ , -SO ₂ NHCOCH ₃ ,-(CH ₂ ) SO ₂ H, -SO ₃ H, -PO ₃ NH ₂ ,- Preferred is selected from the group consisting of PO ₃ H ₂ , -NH ₂ and -N (CH ₃ ) ₂ .

The hydrophilic group-containing photosensitive resin may have an acid value of 5 to 20, preferably an acid value of 5 to 10. When the acid value of the hydrophilic group-containing photosensitive resin is less than 5, development using a water-soluble developer may not be easy, and when the acid value of the hydrophilic group-containing photosensitive resin exceeds 20, phase separation of the composition for forming an electron emission source This is because such a problem may occur that the stability of the composition for electron emission source formation is lowered.

The content of the hydrophilic group-containing photosensitive resin may be 50 to 200 parts by weight, preferably 100 to 150 parts by weight based on 100 parts by weight of the resin component. When the content of the hydrophilic group-containing photosensitive resin is less than 50 parts by weight based on 100 parts by weight of the resin component, the exposure sensitivity is lowered, and when the content of the hydrophilic group-containing photosensitive resin exceeds 200 parts by weight based on 100 parts by weight of the carbon-based material, the flowability of the composition for forming an electron emission source is formed. And printability is not preferred because it may be degraded.

If necessary, in addition to the hydrophilic group-containing photosensitive resin, it may further include a photosensitive resin commonly used in the composition for forming an electron emission source.

The water-soluble photoinitiator serves to initiate crosslinking upon exposure of the photosensitive resin as described above. The photoinitiator is also selected from the water-soluble photoinitiator, so that the composition for forming an electron emission source including the same is easily developed by the water-soluble developer. Specific examples of the water-soluble photoinitiator include thioxanthones, benzophenones, benzyl, hydroxylalkyl ketones, phenacyl thiosulfate, and the like. More specifically, sodium benzoylmethylthiosulphate, anthraquinone-2-sulfonic acid / sodium salt, and the like can be used. Among these, it is also possible to use 2 or more combinations.

By the above-mentioned water-soluble polymer (which may be included in the resin component of the vehicle), a hydrophilic group-containing photosensitive resin, and a water-soluble photoinitiator, the composition for forming an electron emission source of the present invention can be prepared using conventional acetone, ethyl acetate, methyl ethyl ketone, and the like. It can be developed using a water soluble developer instead of a volatile organic solvent. Therefore, the composition for forming an electron emission source (more specifically, the composition for forming an electron emission source that is not exposed) may be first developed by using a water-soluble developer, and the photoresist pattern and the composition for forming an electron emission source may be developed in an organic solvent. When the removal at the same time by using the residue of the composition for forming an electron emission source can be solved the problem that remains in the electron emission source non-forming region.

Such a composition for forming an electron emission source of the present invention may further include an adhesive component or a filler as necessary.

The adhesive component serves to attach the electron emission source to the substrate, and may be, for example, an inorganic binder. Non-limiting examples of such inorganic binders include frit, silane, water glass, and the like, and two or more of these may be mixed and used. The frit may be made of, for example, lead oxide-zinc oxide-boron oxide (PbO-ZnO-B ₂ O ₃ ). Among the inorganic binders, frit is preferable.

The content of the inorganic binder in the composition for forming an electron emission source may be 10 to 50 parts by weight, preferably 15 to 35 parts by weight based on 100 parts by weight of the carbon-based material. When the content of the inorganic binder is less than 10 parts by weight based on 100 parts by weight of the carbon-based material, satisfactory adhesive strength may not be obtained, and when the content of the inorganic binder exceeds 50 parts by weight, printability may be deteriorated.

The filler is a material that serves to improve adhesion of the carbon-based material that is not sufficiently adhered to the substrate, and non-limiting examples thereof include Ag, Al, Pd, TiO ₂ , Al ₂ O _3, and the like.

The composition for forming an electron emission source of the present invention comprising a material as described above may have a viscosity of 3,000 to 50,000 cps, preferably 5,000 to 30,000 cps. If it is out of the viscosity range, a problem may arise that the workability is poor.

The electron emission source manufacturing method according to the present invention uses a composition for forming an electron emission source as described above, and includes developing a composition for forming an electron emission source using a water-soluble developer and removing a photoresist pattern. do.

More specifically, the method for manufacturing an electron emission source, as described above, providing a composition for forming an electron emission source, forming a photoresist pattern defining an electron emission source formation region on the substrate, Printing and exposing the composition for forming an electron emission source on a substrate having a photoresist pattern, developing the exposed composition for forming an electron emission source using a water-soluble developer, and removing the photoresist pattern. And firing the composition for forming an electron emission source.

First, a composition for forming an electron emission source is prepared with the components and contents as described above. Detailed description of the composition for forming an electron emission source is the same as described above, and will be omitted.

On the other hand, a photoresist pattern defining an electron emission source formation region is formed on the substrate. The "substrate" is a substrate on which an electron emission source is to be formed, which may be different depending on the electron emission element to be formed, which is easily recognized by those skilled in the art. For example, the "substrate" may be a cathode when manufacturing an electron emission device having a gate electrode between a cathode and an anode, and an electron emission device having a gate electrode disposed below the cathode. In manufacturing, the insulating layer may be an insulating layer that insulates the cathode and the gate electrode. On the other hand, the photoresist pattern may be formed using any known photoresist pattern forming material.

Then, the prepared composition for forming an electron emission source is printed on the substrate on which the photoresist pattern is formed, and then exposed. At this time, UV exposure can be used normally.

Thereafter, the exposed electron emission source formation composition is first developed with a water-soluble developer. As described above, this is possible because a composition for forming an electron emission source containing a water-soluble polymer, a hydrophilic group-containing photosensitive resin, and a photoinitiator is used.

The aqueous developer may be an aqueous solution of at least one of a group consisting of alkali metals, alkaline earth metals, and carbonates and hydrogencarbonates of ammonium metals, alkaline earth metals, and ammonium as a material capable of ionic bonding with a water-soluble polymer and / or a hydrophilic group-containing photosensitive resin. However, it is not limited thereto. More specifically, it may be an aqueous solution of at least one of the group consisting of Na ₂ CO ₃ , NaHCO ₃ , K ₂ CO ₃ , K ₂ HCO ₃ , (NH ₄ ) ₂ CO ₃ and (NH ₄ ) HCO ₃ . The concentration of the aqueous solution may be 0.2wt% to 3wt%, more preferably 0.5wt% to 2wt%. When the concentration of the aqueous solution used as the developer is less than 0.5wt%, there is a problem in that the composition for forming an electron emission source in the unexposed region cannot be effectively developed, and when the concentration of the aqueous solution used as the developer is 2wt% or more, This is because the problem of excessive increase may occur.

As such, the composition for forming an electron emission source is first developed using a water-soluble developer, and then the photoresist pattern is removed. The photoresist pattern may be removed using a conventional solvent. More specifically, the photoresist pattern is different depending on the material for forming the photoresist pattern, using a conventional organic solvent, for example, an organic solvent such as acetone, ethyl cellosolve or the like or a conventional alkaline solution having a very high pH. , Can be removed.

As such, by first developing the composition for forming an electron emission source using a water-soluble developer and then removing the photoresist pattern, the problem that the residue of the composition for forming an electron emission source remains in the electron emission non-forming region is solved. Can be.

The composition for forming an electron emission source developed as described above is subjected to a firing step. Through the firing step, the carbon-based material in the composition for forming an electron emission source may have improved adhesion to the substrate, at least one vehicle is volatilized, and at least some other vehicle or inorganic binder is melted and solidified to form an electron emission source. It can contribute to the improvement of durability. The firing temperature should be determined in consideration of the volatilization temperature and time of the vehicle included in the composition for electron emission source formation. Typical firing temperatures are 400 to 500 ° C, preferably 450 ° C. If the firing temperature is less than 400 ℃ may cause a problem that the volatilization such as a vehicle is not sufficiently made, if the firing temperature exceeds 500 ℃ may cause a problem that the carbon-based material may be damaged. On the other hand, the firing atmosphere may be carried out in the presence of an inert atmosphere, for example, nitrogen gas, argon gas, neon gas, xenon gas and a mixture of two or more of them in order to prevent degradation of the carbon-based material.

The carbon-based material on the surface of the fired product thus fired is optionally subjected to an activation step. According to one embodiment of the activation step, after applying a solution that can be cured in the form of a film through a heat treatment process, for example, an electron emission source surface treatment agent containing a polyimide-based polymer on the firing result, and then heat treatment Then, the film formed by the heat treatment is peeled off. According to another embodiment of the activation step, the activation process may be performed by forming an adhesive part having an adhesive force on the surface of the roller driven by a predetermined driving source and pressing the surface of the firing product at a predetermined pressure. Through this activation step, the carbon-based material may be exposed or vertically aligned to the electron emission surface.

The electron emission source manufactured as described above forms an electron emission element together with a cathode electrode, an anode electrode, and a phosphor layer, and the electron emission element may be applied to, for example, a display device or a backlight unit.

One embodiment of an electron emission device having an electron emission source of the present invention as described above is referred to FIG. 1. 1 schematically shows an electron emitting device having a triode structure among various electron emitting devices according to the present invention. The electron emission device 200 illustrated in FIG. 1 includes an upper plate 201 and a lower plate 202, and the upper plate is an upper electrode 190 and an anode electrode 180 disposed on the lower surface 190a of the upper substrate. And a phosphor layer 170 disposed on the bottom surface 180a of the anode electrode.

The lower plate 202 has a lower surface substrate 110 disposed in parallel with the upper substrate 190 at predetermined intervals to have an inner space, and a cathode electrode disposed in a stripe shape on the lower substrate 110 ( 120, a gate electrode 140 arranged in a stripe shape to intersect the cathode electrode 120, an insulator layer 130 disposed between the gate electrode 140 and the cathode electrode 120, and the insulator layer ( 130 and an electron emission source hole 169 formed in a portion of the gate electrode 140 and the electron emission source hole 169 are disposed in the electricity supply to the cathode electrode 120 and lower than the gate electrode 140. And an electron emission source 160 disposed therein. The electron emission source 160 is manufactured using the composition for forming an electron emission source as described above. Detailed description of the composition for forming an electron emission source is the same as described above, and thus will be omitted.

The upper plate 201 and the lower plate 202 are maintained in a vacuum at a pressure lower than atmospheric pressure, and the spacer 192 supports the pressure between the upper plate and the lower plate generated by the vacuum and partitions the light emitting space 210. It is disposed between the upper plate and the lower plate.

The anode electrode 180 applies a high voltage required for acceleration of electrons emitted from the electron emission source 160 to allow the electrons to collide with the phosphor layer 170 at high speed. The phosphor of the phosphor layer is excited by the electrons and emits visible light while falling from a high energy level to a low energy level.

The gate electrode 140 serves to facilitate the emission of electrons from the electron emission source 160, and the insulator layer 130 partitions the electron emission source hole 169 and the electrons. It serves to insulate the emission source 160 and the gate electrode 140.

The electron-emitting device of the present invention has been described with an electron-emitting device having a triode structure as shown in FIG. 1 as an example, but the present invention includes not only the triode structure, but also an electron emitting device having another structure including a dipole tube. In addition, it is possible to prevent damage to the electron emission element in which the gate electrode is disposed below the cathode electrode, the gate electrode and / or the cathode electrode due to the arc that is assumed to be caused by the discharge phenomenon, and to focus the electrons emitted from the electron emission source. It can also be used for electron emitting devices with grids / meshes to ensure the safety. On the other hand, it is also possible to apply the structure of the electron emitting device to a display device or a backlight unit.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples are only described for the purpose of more clearly expressing the present invention, and the content of the present invention is not limited to the following examples.

EXAMPLE

Example  One

1 g of carbon nanotube powder (SWNT, manufactured by CNI), a unit represented by Chemical Formula 3, and a unit represented by Chemical Formula 4 are included in 9.5 g of terpineol in a molar ratio of 7: 3, and has a weight average molecular weight of about 10,000. 36g of polymer (30% of solid content), inorganic filler TiO ₂ 10g, inorganic filler Al ₂ O ₃ 30g, TPO 3g as photoinitiator, PETA 0.5g as resin component, PE320 (photosensitive resin), acid value is 5 10g) was added and stirred to prepare an electron emission composition having a viscosity of 30,000 cps.

On the other hand, a positive photo resist was coated on a substrate having a Cr gate electrode, an insulating film, and an ITO electrode with a spin coater, and then exposed and developed to form a photoresist pattern defining an electron emission source formation region. Then, the above-described composition for forming an electron emission source was printed on the substrate on which the photoresist pattern was formed, and irradiated with a parallel exposure machine at an exposure energy of 1000 mJ / cm ² . After exposure, the composition for forming an electron emission source was first developed using an aqueous 0.25 wt% Tetra Methyl Ammonium Hydroxide (TMAH) solution, and then the photoresist pattern was removed using acetone. The composition for forming an electron emission source obtained therefrom was calcined at a temperature of 450 ° C. to form an electron emission source. Subsequently, a substrate using ITO as a fluorescent film and an anode electrode was disposed so as to be oriented with the substrate on which the electron emission source was formed, and a spacer was formed between the substrates to maintain the cell gap between the substrates. The electron emitting device is referred to as sample 1.

Example  2

In Example 1, the unit represented by the formula (3) and the unit represented by the formula (4) in a molar ratio of 7: 3, and instead of a polymer having a weight average molecular weight of about 10,000, and the unit represented by the formula (3) An electron emitting device was manufactured in the same manner as in Example 1, except that the polymer represented by Formula 4 was included in a molar ratio of 7: 3 and a polymer having a weight average molecular weight of about 30,000 was used. This is called sample 2.

Example  3

In Example 1, the unit represented by the formula (3) and the unit represented by the formula (4) in a molar ratio of 7: 3, and instead of a polymer having a weight average molecular weight of about 10,000, and the unit represented by the formula (3) The electron-emitting device was manufactured in the same manner as in Example 1, except that the polymer represented by Formula 4 was included in a molar ratio of 7: 3 and a polymer having a weight average molecular weight of about 50,000 was used. This is called sample 3.

Example  4

In Example 1, except that EB018 (manufactured by UCB, acid value is 15) instead of PE320 (Miwon Co., Ltd., acid value is 5) as a photosensitive resin, and the above Example 1 In the same manner, an electron emission device was manufactured. This is called sample 4.

Evaluation Example-Current Density Evaluation

The current density of Sample 1 was measured using a pulse power source and an ammeter. The results are shown in Table 1 below.

Sample number Current density (current density at 5 V / μm, unit is μA / cm ² ) One 150 2 800 3 300 4 300

According to Table 1, it can be seen that the electron emission device according to the present invention has excellent current density.

When the composition for forming an electron emission source of the present invention is used, a two-stage development process for first developing the composition for forming an electron emission source using a water-soluble developer and then developing a photoresist pattern is possible. As a result, the development of the electron emission source forming composition and the photoresist pattern at the same time using an organic solvent can be prevented from remaining the residue of the resulting electron emission source forming composition. Therefore, by using the electron emission source, an electron emission device having improved reliability can be obtained.

Claims (12)

A composition for forming an electron emission source comprising a carbonaceous material, a vehicle, a hydrophilic group-containing photosensitive resin, and a water-soluble photoinitiator. The electron emission source of claim 1, wherein the vehicle comprises a water-soluble polymer having a weight average molecular weight of 1,000 to 50,000, including a unit represented by Formula 1 and a unit represented by Formula 2 below. Composition for: <Formula 1>

<Formula 2>

In Formulas 1 and 2, R ₁ and R ₄ are each independently a substituted or unsubstituted C ₁ -C ₂₀ alkylene group, a substituted or unsubstituted C ₂ -C ₂₀ alkenylene group, a substituted or unsubstituted C ₃ -C ₂₀ cycloalkylene group A substituted or unsubstituted C ₆ -C ₂₀ arylene group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkylene group, or a substituted or unsubstituted C ₂ -C ₂₀ heteroarylene group; R ₂ and R ₅ are each independently a bonded, substituted or unsubstituted C ₁ -C ₂₀ alkylene group, a substituted or unsubstituted C ₂ -C ₂₀ alkenylene group, a substituted or unsubstituted C ₃ -C ₂₀ cycle An alkylene group, a substituted or unsubstituted C ₆ -C ₂₀ arylene group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkylene group, or a substituted or unsubstituted C ₂ -C ₂₀ heteroarylene group; R ₃ and R ₆ are each independently a substituted or unsubstituted C ₁ -C ₂₀ alkyl group, a substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, a substituted or unsubstituted C ₃ -C ₂₀ cycloalkyl group, a substituted or An unsubstituted C ₆ -C ₂₀ aryl group, a substituted or unsubstituted C ₂ -C ₁₉ heterocycloalkyl group, or a substituted or unsubstituted C ₂ -C ₂₀ heteroaryl group; Z is -OA, -COOA, -SO ₂ A, -SO ₂ NH ₂ , -SO ₂ NHCOT ¹ , -T ² SO ₂ A, -SO ₃ A, -PO ₃ NH ₂ , -PO ₃ A ₂ ,- A hydrophilic group selected from the group consisting of NH ₂ and —N (T ¹ ) ₂ ; A is hydrogen, an alkali metal, or -NQ ¹ Q ² wherein Q ¹ and Q ² are each independently hydrogen, a C ₁ -C ₂₀ alkyl group or a C ₆ -C ₂₀ aryl group; T ¹ is a C ₁ -C ₂₀ alkyl group, a C ₆ -C ₂₀ aryl group or a C ₂ -C ₂₀ heteroaryl group; T ² is a C ₁ -C ₂₀ alkylene group, C ₆ -C ₂₀ arylene group or C ₂ -C ₂₀ heteroarylene group, the composition for forming an electron emission source. The method of claim 1, wherein Z is -OH, -COOH, -SO ₂ H, -SO ₂ NH ₂ , -SO ₂ NHCOCH ₃ ,-(CH ₂ ) SO ₂ H, -SO ₃ H, -PO ₃ NH ₂ , -PO ₃ H ₂ , -NH ₂ and -N (CH ₃ ) _{2 It} is a hydrophilic group selected from the group consisting of the composition for forming an electron emission source. The method of claim 1, wherein the hydrophilic group-containing photosensitive resin is selected from the group consisting of an acrylate resin, a benzophenone resin, an acetophenone resin, a thioxanthone resin, an epoxy resin, and a urethane resin substituted with a hydrophilic group. The composition for forming an electron emission source. The method of claim 4, wherein the hydrophilic group in the hydrophilic group-containing photosensitive resin is -OA, -COOA, -SO ₂ A, -SO ₂ NH ₂ , -SO ₂ NHCOT ¹ , -T ² SO ₂ A, -SO ₃ A, -PO ₃ NH ₂ , -PO ₃ A ₂ , -NH ₂ and -N (T ¹ ) ₂ ; A is hydrogen, an alkali metal, or -NQ ¹ Q ² wherein Q ¹ and Q ² are each independently hydrogen, a C ₁ -C ₂₀ alkyl group or a C ₆ -C ₂₀ aryl group; T ¹ is a C ₁ -C ₂₀ alkyl group, a C ₆ -C ₂₀ aryl group or a C ₂ -C ₂₀ heteroaryl group; T ² is a C ₁ -C ₂₀ alkylene group, a C ₆ -C ₂₀ arylene group or a C ₂ -C ₂₀ heteroarylene group, characterized in that the composition for electron source formation. The method of claim 4, wherein the hydrophilic group is -OH, -COOH, -SO ₂ H, -SO ₂ NH ₂ , -SO ₂ NHCOCH ₃ ,-(CH ₂ ) SO ₂ H, -SO ₃ H, -PO ₃ NH ₂ , -PO ₃ H ₂ , -NH ₂ and -N (CH ₃ ) _{2 The} composition for forming an electron emission source, characterized in that selected from the group consisting of. The composition for electron emission source formation according to claim 1, wherein the hydrophilic group-containing photosensitive resin has an acid value of 5 to 20. The electron emission source of claim 1, wherein the water-soluble photoinitiator is at least one selected from the group consisting of thioxanthones, benzophenones, benzyls, hydroxylalkyl ketones, and phenacyl thiosulfate. Composition. Providing a composition for forming an electron emission source of any one of claims 1 to 8; Forming a photoresist pattern on the substrate defining an electron emission source formation region; Printing and exposing the composition for forming an electron emission source on a substrate on which the photoresist pattern is formed; Developing the exposed composition for forming an electron emission source with a water-soluble developer; Removing the photoresist pattern; And Firing the developed composition for electron emission source; Electron emitter manufacturing method comprising a. 10. The method according to claim 9, wherein the developing step of the composition for forming an electron emission source is performed using at least one water-soluble developer selected from the group consisting of alkali metals, alkaline earth metals and carbonates and hydrogencarbonates of ammonium. Source manufacturing method. The method of claim 9, wherein the developing step of the composition for forming an electron emission source is Na ₂ CO ₃ , NaHCO ₃ , K ₂ CO ₃ , K ₂ HCO ₃ , (NH ₄ ) ₂ CO _3, and (NH ₄ ) HCO ₃ . A method for producing an electron emission source, characterized in that performed using at least one water-soluble developer selected from the group consisting of. A first substrate and a second substrate disposed to face each other; A cathode electrode formed on the first substrate; An electron emission source formed to be electrically connected to the cathode electrode; An anode electrode formed on the second substrate; And A fluorescent layer emitting light by electrons emitted from the electron emission source; The electron emission device of claim 1, wherein the electron emission source is manufactured using the composition for forming an electron emission source of any one of claims 1 to 8.

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